ARIC is a prospective epidemiologic study conducted in four U.S. communities: Washington County, MD; Forsyth County, NC; Jackson, MS; and Minneapolis, MN. The study is designed to monitor the trends in incidence and mortality of coronary heart disease (CHD) and heart failure in communities, and to investigate the etiology, natural history, and progression of subclinical and clinical cardiovascular disease such as CHD, heart failure, and stroke. Accordingly, ARIC includes a Community Surveillance Component and Cohort Study Component. For the community surveillance, the four communities are investigated to determine the occurrence of hospitalized myocardial infarction and CHD deaths in approximately 800,000 men and women aged 35-84 years. Starting in 2006, surveillance of inpatient (ages 55 years and older) and outpatient heart failure (ages 65 years and older) is included for the events beginning in 2005. Under the new contract, community surveillance will continue to monitor long-term trends in hospitalized MI, CHD deaths, and heart failure (inpatient and outpatient). For the cohort study, approximately 4,000 individuals aged 45-64 years were recruited by probability sampling from each of the four communities under surveillance. A total of 15,792 participants (11,478 whites, 4,266 African Americans, and 48 other) received an extensive baseline examination in 1987-1989. Three repeat examinations were conducted in 1990-92, 1993-95, and 1996-98. The examinations collected information on demographics, psycho-social and behavioral factors, dietary intakes, physical measurements, and biological and genetic markers. Under the new contract, the surviving cohort members will receive another clinic exam to characterize heart failure stages, identify genetic and environmental factors leading to ventricular dysfunction and vascular stiffness, and assess longitudinal changes in pulmonary function and identify determinants of its decline. Participants are also contacted twice a year by telephone to assess health status. Under the new contract, the study will also be enhanced with cardiovascular outcomes research to assess quality and outcomes of medical care for heart failure risk factors and heart failure.